Anti-slaking buffing compositions



t because of the short storage life.

United States Patent Ofifice,

2,847,290 a e t d A 9.58

2,s 47,290 ANI-I-SLAKING BUFFING coivirosmoNs Byron E. Marsh,Brookfield, and Richard L. Betcher,

Chicago, 111., assignors to Armour and Company, Chicago, 111., acorporation of Illinois No Drawing. Application April 10, 1957 SerialNo. 651,828

6 Claims. c1. 51-304 This invention relates to improved buffingpositions. In one of its aspects, this invention relates to lime buflingbars having improved anti-slaking properties.

Conventional bufiing compositions in use for butting nickel, nickelalloys, copper, brass, zinc, aluminum, etc., have proven unsatisfactoryin many respects. Such compositions usually contain lime and are used inthe form of bars. In use these bars are rubbed against the butting wheeland the abrasive is applied to the wheel by melting binder brought aboutthrough the heat of friction.

The production of lime compositions has caused problems in the buifingindustry for years. An insoluble lime soap is often formed when mixingthe calcium and magnesium oxide abrasives and the fatty acid binder inthe presence of moisture. When this occurs in the kettle it is necessaryto break the hard cellular soap into pieces that can be usually removed,since heat will only char the soap, not melt it. In addition to soapformation, the most pressing problem from a consumer point of view isslaking. This term is used to describe the hydration of the hard oxidesto the soft hydroxides in the presence of atmospheric moisture andnormally takes place within one to three weeks after formation of thelime bar unless an airtight container is used for storage of thecomposition. As hydration occurs the slaked lime reacts with the fattyacid binder and the bar flakes and eventually crumbles. In thiscondition of course it cannot be used in bufiEing operations. problemsomewhat by the use of quality controlled materials, close supervisionin manufacture, and the use of expensive airtight containers similar tothe vacuum sealed food containers. However, even with these precautions,storage of lime bars for any length of time is not practiced and ordersare filled only when received. It is obvious, therefore, that thereexists a need for an anti-slaking additive in lime bufling compositions.

In accordance with the present invention we have provided ananti-slaking additive for lime buffing compositions which enablesbufling ba compounders to produce bars for stock, which they have beenunable to do before This makes possible easier production scheduling andthe preparation of larger sized batches. Also, it enables the use of acheap paper container in place of an' expensive airtight metal containeror foil.

Our anti-slaking additives are N-aliphatic-trimethylene diamines whichcan be represented by the structural formula RNHCH CH CH NH wherein R isan aliphatic hydrocarbon radical containing from 8 to 22 carbon atoms.Examples of aliphatic radicals coming within the definition of R includeoctyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, octadecenyl,octadecadienyl, octadecatrienyl, and statistical mixtures of theforegoing radicals as are contained in naturally occurring oils and fatssuch as tallow, soybean oil, coconut oil, and the like. The mixture ofaliphatic hydrocarbon radicals contained in tallow is comprised ofapproximately 45% by weight of octadecenyl, 25% octadecyl, and 30%hexadecyl radi- The industry has alleviated the v .2. e x mp e f-p eferd at ak n dd t r s nd d N-tallow -trimethylene diamine,Neoctadecyl-trirnethylene am ne N sxa e y msth c d ami e.

The improved ;anti slaki ng by lime bulfing compositions of he ssm n Qwnt -n. Q abou o 89% by weight of lime, such as Vienna lime, as theabrasive element, from about 12 to 18% of a saturated fatty acid havinga titer of at least 40 C., preferably'having an iodine value not inexcess of 7.0, from about 12 to 18% of an animal or vegetable oilglyceride, and from about 1.5 to about 5.0%, preferably about 5.0% ofour antislaking additive as described above. If desired, the abrasiveelement can contain in addition to the lime conventional materials suchas emery, silicon carbide, tripoli, or the like.

The bufiing compositions of the present invention can be prepared byblending together the anti-slaking additives, saturated fatty acid, andanimal oil at a temperature of about 190 F. after which the abrasivematerial is added to the molten material with mixing until a smoothmixture is obtained. The molten paste can then be put into forms andallowed to cool and harden.

The following example Will illustrate this invention in the manner inwhich it may be practiced, but it is to be understood that this exampleis not to be construed as unduly limiting:

1 Example Three series of two bufiing bars, A and B, were prepared andobserved under difierent storage conditions for slaking. The bars wereprepared in the manner described above. Bar A contained 15% by weight ofstearic acid having a titer of 54 C. and an iodine value of 7, 15%acidless tallow and 70% lime composed of 50% CaO and 50% MgO. Bar Bcontained 15% by weight of stearic acid having a titer of 54 C. and aniodine value of 7, 15% acidless tallow, 5% N-tallow-trimethylene diamineand 65% lime composed of 50% CaO and 50% MgO. Each of the bars werestored in unsealed containers.

One group of bars was stored in a humidity cabinet of F. and 93%relative humidity. Bar A slaked in less than 72 hours. Bar B showed noevidence of slaking after 96 hours.

Another group of bars was stored in an air oven at F. Bar A slaked in 6days. Bar B showed no evidence of slaking after 38 days.

Still another group was stored under ordinary conditions, but unwrapped.Bar A slaked after 14 days. Bar B showed slaking on the surface onlyafter 38 days of storage.

While this invention has been described and exemplified in terms of itspreferred embodiments, those skilled in the art will appreciate thatmodifications can be made without departing from the spirit and scope ofthe invention.

We claim:

1. An improved lime bufiing composition containing as an anti-slakingadditive from about 1.5% to about 5.0% by weight of a compound havingthe formula RNHCH CH CH NH wherein R is an aliphatic hydrocarbon radicalhaving from 8 to 22 carbon atoms.

2. An improved lime bufling composition containing as an anti-slakingadditive from about 1.5 to about 5.0 weight percent ofN-tallow-trimethylene diamine.

3. An improved lime bufiing composition containing as an anti-slakingadditive about 5.0% by weight of N-tallow-trimethylene diamine.

4. A lime buffing composition consisting of about 65 to 80% by weight ofVienna lime, about 12 to 18% of a saturated fatty acid having a titer ofat least 40 C., from about 12 to about 18% of tallow and 1.5 to about 45.0% by Weight of a compound having the formula References Cited in thefile of this patent RNHCH CH CH NH wherein R is an aliphatic hydrocarbonradical having from 8 to 22 carbon atoms. UNITED STATES PATENTS 5. Acomposition according to claim 4 wherein the 2,078,876 I-Iennessey Apr.27,1937 saturated fatty acid is stearic acid and R is a mixture of 52,417,800 Weisser Mar. 18, 1947 aliphatic hydrocarbon radicals ascontained in tallOW. 2,482,667 Gray Sept. 20, 1949 6. A lime bufiingcomposition consisting of about 65% 2,606,829 Chester Aug. 12, 1952 byweight of Vienna lime, 15% stearic acid, 15% aCidl S 2,642,348 StierJune 16; 1953 tallow, and 5.0% of N-talloW-trimethylene diamine.

6. A LIME BUFFING COMPOSITION CONSISTING OF ABOUT 65% BY WEIGHT OFVIENNA LIME, 15% STEARIC ACID, 15% ACIDLESS TALLOW, AND 5.0% OFN-TALLOW-TRIMETHYLENE DIAMINE.